In failure analysis of a semiconductor device, generally, a failure part is narrowed to a narrow region by using a failure part specifying apparatus for, e.g., OBIRCH (Optical Beam Induced Resistance Change) or a PEM (Photon Emission Microscope), then the failure part is locally processed by using an FIB (Focused Ion Beam) or the like, and physical analysis is conducted with the use of observing means such as an SEM (Scanning Electron Microscope) or a TEM (Transmission Electron Microscope).
At the time of performing the physical analysis with respect to the part narrowed by the failure part specifying apparatus, since an observation image is switched from an optical image provided by an optical microscope to an SEM image provided by an electron microscope, an observation magnification or how an acquired image is seen greatly varies. As a result, an observation part becomes hard to find, a mark that can be a guide is required. Therefore, before cleaving a wafer and setting it with respect to the electron microscope, marking is carried out on the failure part specifying apparatus side, and a failure is detected by the electron microscope relying on a provided mark and a layout drawing of a sample. The sample from which a failure has been detected is cut into, e.g., a 1-square-cm small piece while using the mark provided on the failure part specifying apparatus side as a guide, and then it is subjected to a cross-sectional analysis.
If the sample is a laminated structure formed of a plurality of layers, the respective layers are sequentially delaminated from the upper side and gradually analyzed, and detailed analysis is performed from a cross-sectional direction when a failure is confirmed. If an upper layer has no problem and lower layers should be subjected to analysis, since a marking provided on the upper layer by deposition or the like disappears simultaneously with layer delamination, there is a problem that marking processing must be performed again on the failure part specifying apparatus side every time delamination occurs.
Therefore, a marking method that enables failure analysis with a high accuracy and high efficiency is demanded.